RU2688175C1 - Radiometric multivariate plant - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to measurement equipment in nuclear power engineering. Radiometric multivariate plant comprises a measuring system consisting of three independent measuring channels of controlling volumetric radioactivity of inert gases, aerosols and iodine, each of which comprises the relevant detector comprising at least one detection unit and a device for accumulation and processing of the measurement results, besides, it comprises a sampling circuit, which includes two independent air feed lines, herewith it is equipped with a device for automatic support of air flow rate including an integral pumping device in the form of a pump of constant rarefaction arranged on the outlet air exhaust pipeline, herewith each independent air feed line is equipped with an electrically controlled valve and an air flow rate measuring device both connected with the device for accumulation and processing of the measurement results containing an analog-to-digital conversion unit and a microprocessor for statistical processing of the measurement results, herewith every device for accumulation and processing of the measurement results is connected with a device for control and display of the measurement results.

EFFECT: higher reliability of the radiometric plant operation.

1 cl, 1 dwg

Description

The claimed technical solution relates to the field of measurement technology in nuclear energy, in particular at nuclear power plants (NPP), and is intended for radiation monitoring of gas and aerosol emissions of a reactor into the ventilation pipe of a nuclear power plant, namely to measure and monitor the volumetric activity of radioactive emissions containing aerosols, pairs iodine-131 and inert gases.

Known spectrometry gas monitor gamma radiation, including a device for detecting gamma radiation of gaseous media containing a measuring chamber housed in a lead protection unit, while the detection device is connected to a sampling system and a digital spectrum analyzer, the spectrometric monitor is equipped with a flow meter and a device for storing and processing information connected to a digital spectrum analyzer, while the detection device includes a semiconductor detector of gamma radiation on the basis of extremely pure germanium, placed in a measuring chamber made in the geometry of the vessel Marinelli, and equipped with an electric cooler, the protective unit is made in the form of 4π-protection and is a container with double walls forming an internal volume filled with lead shot, while the upper part of the protective the unit is made removable, the sampling system provides a pipeline for supplying a controlled gaseous medium and a pipeline for supplying compressed air, fitted with a shut-off valve, going into the supply pipeline and the environment on which the flow meter is installed, the sampling system is equipped with a control controller associated with an information storage and processing device, and is connected to a detection device with supply and removal pipelines (environment utility patent No. 91779, publication date 27.02.2010, IPC G21C 17 / 032 "Device for detecting gamma-radiation from gaseous media and spectrometric gas monitor for gamma-radiation").

A disadvantage of the known device lies in the fact that it is equipped with a single line of controlled gaseous medium, which is intended only for monitoring gamma radiation of radioactive gases with a single detection device. In this line, solenoid valves are used, placed both before the detection device and after it, which complicates the operation control, namely, in terms of controlling the flow of the gaseous medium. Using your own pump in this device is not provided.

Known monitor of radioactive aerosols, iodine and inert gases with continuous monitoring of air emissions in ventilation communications or work areas, on one pneumatic line which is placed sequentially: aerosol detection unit, iodine detection unit, inert gas detection unit, control valve and pump (see Functional diagram of the installation of PING 206S, RAMSYS series, on the site http://ristec.ru/downloads/ping_206s_eng.pdf).

In this device, three detection units (aerosols, iodine, inert gases) are sequentially located in the first pneumatic line, and the second pneumatic parallel line is designed to test the sample under laboratory conditions, that is, the parallel line does not participate in operational analysis. Automatic adjustment of the air flow rate is not provided. Regulation of the air flow in the first line is carried out manually by a control valve, which is placed in front of the adjustable pump, which leads to a decrease in measurement accuracy, a decrease in reliability of operation, and an excessive flow of the controlled gaseous medium.

In the analogue, the constant volume of the sample of the measured gas medium is automatically maintained per unit of time with the help of one controlled pump during normal operation. But when a managed pump fails, the installation cannot operate without a pump by connecting it to the NPP central air line and it is not possible to connect back-up uncontrolled pumps.

In addition, the analogue lacks a flow meter and a controlled valve to ensure the same sample volume, which leads to a decrease in measurement accuracy and reliability of the device.

The prototype is the installation radiometric RKS-07P. In the structural-functional scheme of the РКС-07П installation (ЖШ1.289.404С1) without its own pump, a unit for detecting inert gases of the coarse subrange (based on the flow chamber) is placed on one pneumatic line. From this, the measurement results, passing through the connecting device, enter the single device processing. (Radiometric installation РКС-07П. Specifications 95 2191-90 ЖШ1.289.404. ТУ Installation radiometric РКС-07П. Operation manual. ЖШ1.289.404.РЭ).

On the second parallel pneumatic line consistently placed:

a device for detecting alpha and beta aerosols, consisting of a detecting unit and one block of amplification and processing of pulse signals, from which the measurement results are transmitted to a single processing device;

then, an iodine detection device, consisting of an iodine detection unit and two amplification and pulse signal processing units, from which measurement results are transmitted to a single processing device;

as well as an inert gas detection unit of the sensitive subrange based on the ionization chamber, the measurement results from which are transmitted to the amplification and processing unit of pulse signals placed in the device for detecting iodine.

Flow meters and pump can be connected both at the beginning and at the end of a single pneumatic line. In the same places the lines install valves, and there are no controllable valves.

The disadvantage of the prototype is that the RKS-07P installation does not have its own pump, which leads to a decrease in reliability of operation and an increase in the time required to connect an external pumping system.

The disadvantages of the prototype include the fact that the air flow in the РКС-07П is regulated manually, that is, manually operated valves, which are adjustable based on the readings of a single flow meter, that is, there are no controllable valves in the functional diagram.

The given configuration of the structural-functional scheme does not support a constant sample volume of the measured gaseous medium per unit of time, which reduces the reliability of operation and the functionality of the installation, including the possibility of automation.

The objective of the proposed technical solution is to increase the reliability of the radiometric installation.

The problem is solved due to the fact that the installation is a radiometric multiparameter containing a measuring system consisting of three independent measuring channels for controlling the volume radioactivity of inert gases, aerosols and iodine, each of which contains a corresponding detection device containing at least one detection unit and an accumulation device and processing the measurement results, as well as containing the sampling path, which includes two independent lines of air supply, installation of It is equipped with an automatic air flow rate support device that includes a single pumping device in the form of a constant vacuum pump placed in the air exhaust outlet, each independent air supply line equipped with an electrically controlled valve and an air flow velocity measuring device associated with the device accumulating and processing the measurement results, including an A / D conversion unit and a microprocessor for statistical processing of measurement results, while Each device for the accumulation and processing of measurement results is associated with a device for controlling and displaying measurement results.

The use of a single pumping device in the radiometric installation in the form of a constant vacuum pump placed in the outlet air discharge pipe allows using only one pump and creating a constant equal vacuum in all pneumatic lines, which allows to increase the reliability and efficiency of the installation.

The use of an electrically controlled valve and a device for measuring the air flow rate associated with a device for accumulating and processing measurement results, including a microprocessor, allows you to quickly and automatically monitor and regulate the air flow in the sample, which maintains the isokinetic mode of air sampling.

In addition, in this installation it is possible to work without a constant vacuum pump by connecting it to the central air line of the NPP or, in another embodiment, using back-up uncontrolled pumps in case of failure of the permanent vacuum pump, which increases the reliability of the installation by providing equivalent duplication.

Each device for accumulation and processing of measurement results provides preliminary processing of signals from the detection units in the form of analog pulses by means of their analog-digital conversion and digital processing, which increases the reliability, efficiency and accuracy of the device.

The presence of distinctive features in the claimed technical solution allows to make a conclusion about its compliance with the condition of patentability "novelty".

The essential features of the claimed invention, predetermining the receipt of the specified technical result, do not explicitly follow from the prior art, which allows to make a conclusion about the compliance of the invention to the condition of patentability "inventive step".

The condition of patentability "industrial applicability" is confirmed by the example of a specific implementation.

The essence of the technical solution is illustrated in FIG. 1, which depicts a structural-functional diagram of a radiometric multiparameter installation.

The radiometric multiparameter installation consists of three independent measuring channels for monitoring the volume radioactivity of the gaseous medium.

One measuring channel, designed to control the radioactivity of inert gases, contains a device for detecting the volumetric activity of beta-active inert gas radionuclides (a device for detecting inert gases), consisting of two blocks 1 and 2 for detecting coarse and sensitive subranges, and a device for accumulating and processing the results of measurements 3 (DNA of inert gas measurement results) volumetric activity of beta-active radionuclides.

The second measuring channel, designed to control the radioactivity of aerosols, contains a device for detecting the volumetric activity of alpha and beta-radioactive aerosols (an aerosol detection device), consisting of one aerosol detection unit 4, and a device for accumulating and processing the results of measurements 5 (AERO aerosol measurement results) .

The third measuring channel, designed to control the radioactivity of iodine, contains a device for detecting the volumetric activity of iodine ¹³¹ I isotope (a device for detecting iodine), consisting of one unit 6 for detecting iodine, and a device for accumulating and processing the results of measurements 7 (IO measurement results of iodine).

The inlet pipeline 8 of the radiometric installation is connected to the air sampling device (not shown in the figure) from the NPP ventilation pipe, the output pipe 9 of the radiometric installation through which the gaseous medium is removed after the measurements are made, is connected to the NPP air exhaust system (not shown in the figure ).

The radiometric unit is equipped with an automatic air flow rate support device that includes a single pumping device 10 in the form of a constant vacuum pump placed in the exhaust air discharge pipe 9.

The radiometric installation is equipped with a sampling path, consisting of two independent lines - gas and aerosol-iodine.

In the gas line there are two blocks 1 and 2 for detecting inert gases of the coarse and sensitive subranges.

In the aerosol-iodine line, the detection unit 4 aerosols and the detection unit 6 iodine are placed sequentially.

In addition, each independent line is equipped with electrically controlled valves 11 and 12, located in front of the detection units 1 and 2 in the gas line, and behind the detection units 4 and 6 - in the aerosol-iodine line.

Also in the gas line is placed the device 13 measuring the flow rate of air placed behind the blocks 1 and 2 of the detection of inert gases, and in the aerosol-iodine line the corresponding device 14 measuring the speed of air flow placed behind the controlled valve 12.

In each line, the electrically controlled valve and the device for measuring the flow rate of air are connected to one measuring instrument UNO, including a microprocessor.

The measurement results DNA is used in all measuring channels - control of inert gases, aerosols, iodine, while the configuration of its software for the problem being solved is set through the program menu.

The inert gas detection device consists of two detection units 1 and 2, each of which is connected to the DNA of 3 inert gas measurements, the firmware of which performs the task of detecting inert gases of the coarse and sensitive subranges.

The aerosol detection device consists of the aerosol detection unit 4 associated with the DNA measurement results of aerosol 5, the embedded software of which performs the task of aerosol detection.

The device for detecting iodine consists of a unit 6 for detecting iodine, associated with the DNA 7 of iodine measurement results, the embedded software of which performs the task of detecting iodine.

All DNA measurement results associated with a single device 15 controls and display the results of measurements, which, in turn, is connected with the automated system of radiation monitoring of nuclear power plants (not shown in Fig.) And connected to external alarm devices, providing a generalized visual and audible exceeding of installed thresholds or malfunctions.

Filters (not shown) are placed in the functional diagram of the radiometric installation: in one independent air supply line an aerosol and iodine filter is installed in front of the inert gas detection device, in another line - an aerosol filter is installed between the aerosol detection device and the iodine detection device.

Installation radiometric multiparametric works as follows.

The controlled air sample is taken using an air sampling device (not shown in Fig.), The inlet of which is located in the ventilation system of the nuclear power plant, and the outlet is connected to the inlet pipeline 8 of the radiometric installation.

Next, the air sample simultaneously enters the two separate pneumatic lines of the sampling path of the radiometric installation: gas and aerosol-iodine.

In the gas line, an air sample passes through a controlled valve 11, which maintains a predetermined volumetric flow rate and ensures that the sample is isokinetic, and the valve control signal 11 is supplied from the DNA measurement system 3 of inert gases of the inert gas detection device.

Next, the air sample that enters the gas line passes through the filter, where it is purified from aerosols and iodine isotopes, after which it enters the inert gas detection device.

Then the air sample passes through the device for measuring the flow rate of air 13, generating a signal to the UNO 3 inert gas measurement results of the inert gas detection device, and based on this signal, the UNO 3 generates a control signal by a controlled valve 11 located at the beginning of the gas line.

A sample that enters the aerosol-iodine line passes through an aerosol detection device, then passes through a filter in which it is purified from aerosols, and enters the iodine detection device.

Then the air sample passes through the controlled valve 12, which maintains the specified volumetric flow rate and ensures the isokinetic sampling, then goes to the flow rate measurement device 14, which produces a signal corresponding to the current air flow rate. This signal enters the AEC 5 of the results of aerosol measurements of the aerosol detection device, which produces a control signal for the controlled valve 12.

Similarly, the device for measuring the flow rate 14 produces a control signal, which is supplied to the UE 7 of the iodine measurement results of the iodine detection device, which produces a control signal for the controlled valve 12.

Next, air samples in the gas and aerosol-iodine lines are combined in the output pipe 9 and fed to the pumping device 10, which creates a vacuum in the pipeline. From the outlet of the pumping device 10, the combined air sample is fed back into the ventilation pipe of the nuclear power plant.

If it is necessary to temporarily replace the standard pump, an external pumping device is used in the form of connection to the central air line of the NPP or use of back-up uncontrolled pumps.

Measurement of volumetric activity in the gas channel is as follows.

Blocks are used for detecting coarse 1 and sensitive 2 subbands. The detection unit 2 of the sensitive subrange is made on the basis of the ionization chamber and produces a sequence of electrical pulses, the duration of which is inversely proportional to the volume activity of beta-active inert gas radionuclides in the air sample under study. The URA 3 results of measurements of inert gases of this detection unit 2 inert gases measures the pulse duration and converts these values into digital values of volumetric activity.

The detecting unit 1 of inert gases of the coarse subrange is made on the basis of a flow chamber with a scintillation detector and generates a sequence of statistically distributed analog pulses, the amplitude of which is proportional to the energy, and the count rate — the volume activity of beta active radionuclides of inert gases in the air sample under study.

The UMA 3 measurement results of inert gases of this detecting unit 1 digitize analog pulses with an analog-digital converter, accumulates pulses in the form of a spectrum, and then counts the number of pulses in a given zone of the spectrum. The resulting intermediate value is converted to a volumetric activity.

The results of volumetric activity of inert gases are displayed on the indicator of the DNA of the 3rd measurement results of inert gases are recorded in the archive of the device 15 accumulation and display of measurement results, as well as transferred to the upper level in the automated control system of nuclear power plants.

The results are presented in two forms: integral (accumulated and averaged from the beginning of the work shift to the current time) and differential (volumetric activity, measured during the last measurement time interval), while the differential form shows the dynamics of changes in volumetric activity. In case of exceeding the established threshold values of the measured parameters of volumetric radioactivity, the light and sound alarms are activated.

Measurement of volumetric activity in the aerosol-iodine line is as follows.

The detecting unit 4 alpha- and beta-volume activity of aerosols contains two detectors operating in a combined (operational measurement during sampling of air) and placed (measured after one day after sampling, during settling of the sample) modes.

A scintillation detector is used, the output of which is a sequence of statistically distributed analog pulses, the amplitude of which is proportional to the energy, and the counting rate the volume activity. The DNA AO 5 results of aerosol measurements digitizes pulses using an analog-to-digital converter, accumulates pulses in the form of a spectrum, after which the spectrum is divided into alpha and beta zones, in each zone the number of pulses is calculated separately. The resulting intermediate values are converted to the alpha and beta volume activity of aerosols.

The results of the alpha and beta volume activity of aerosols are displayed on the indicator of the DNA of the 5 aerosol measurements are recorded in the archive of the device 15 accumulation and display of measurement results, as well as transferred to the upper level in the automated radiation monitoring system of nuclear power plants.

The results of measuring the volumetric activity are presented in two forms: integral and differential.

The detecting unit 6 of volumetric activity of iodine operates in a combined mode. A scintillation detector is used, the output of which is a sequence of statistically distributed analog pulses, the amplitude of which is proportional to the energy, and the counting rate the volume activity. The DNA of the results of measurements of iodine 7 digitizes pulses using an analog-to-digital converter, accumulates pulses in the form of a spectrum, after which the spectrum is divided into the main and compensation zones, and in each zone the number of pulses is calculated separately. The obtained intermediate values are converted to the volumetric activity of iodine. In this case, compensation is made for interfering nuclides.

The obtained results of iodine volumetric activity are displayed on the indicator UNO 7 of the results of iodine measurements, are recorded in the archive of the accumulation device 15 and display the results of measurements, and are transmitted to the upper level in the automated radiation monitoring system of NPP.

The results of measuring the volumetric activity are presented in two forms: integral and differential. In case of exceeding the established threshold values of the measured parameters of volumetric radioactivity, the light and sound alarms are activated.

Thus, the implementation of a radiometric multiparameter installation, equipped with an automatic air flow rate support device, includes a single pumping device in the form of a constant vacuum pump with the possibility of replacing the pump with an external pumping device that allows you to create the same vacuum in two pneumatic lines, increases the efficiency of the installation and leads to increased reliability her work.

Each independent air supply line, equipped with an electrically controlled valve and a device for measuring the air flow velocity, associated with a device for accumulating and processing measurement results, provides an isokinetic mode of air sampling and increases the reliability of the installation.

An accumulation device and processing of measurement results, containing an analog-to-digital conversion unit and a microprocessor for statistical processing of measurement results, provide pre-processing of signals from detection units in the form of analog pulses through their digital processing, which increases the reliability, efficiency and accuracy of the device.

Claims (1)

A radiometric multiparameter installation containing a measuring system consisting of three independent measuring channels for controlling the volume radioactivity of inert gases, aerosols and iodine, each of which contains a corresponding detection device containing at least one detection unit and a device for accumulating and processing measurement results, as well as containing a sampling path, which includes two independent lines of air supply, characterized in that it is equipped with an automatic device maintaining an air flow rate that includes a single pumping device in the form of a constant vacuum pump placed on the outlet air discharge pipe, each independent air supply line equipped with an electrically controlled valve and an air flow velocity measuring device connected to the device accumulating and processing the measurement results, containing an analog unit -digital conversion and microprocessor for statistical processing of measurement results, with each accumulation device and about abotki measurement results related to the control and display measurement results.

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